Automotive frame-straightening equipment typically includes one or more pulling towers attachable to and adjustable on a bed or frame. The usual tower will include a base affixed to the bed and an upright support rising therefrom and having at its upper end a sheave over which is trained a chain or the like. The tower is hollow or of channel section and the chain extends downwardly inside the tower and is then trained under a second sheave and thence forwardly for connection to the load represented by the damaged part of the vehicle. A hydraulic cylinder is connected to the chain and operates to pull the chain downwardly over the top sheave and upwardly about the second sheave. In order to obtain pulls at the proper angle, it is known to arrange the shaft for the second sheave in such manner that its vertical position can be changed. This is commonly effected by providing the tower with a plurality of vertically spaced openings into selected pairs of which the shaft may be installed. See, for example, the U.S. Pat. No. 3,566,666 to Berendt. The U.S. Pat. No. 3,992,919, to Jarman, shows a portable pulling mechanism in which the upright is provided with a plurality of rearwardly and upwardly inclined slots for selectively receiving a sheavesupporting shaft.
According to the present invention, prior structures are vastly improved by providing within the channel-section tower a plurality of pairs of notches for selectively receiving the shaft. The arrangement is such that the resultant of the pulling forces retains the shaft in its selected notches. Handle means is provided for changing the shaft position when the pulling forces are removed. The handle means is part of a shaft carrier that extends rearwardly into the tower and has a rear portion adapted to ride the rear wall of the tower during changes in the position of the shaft. The interior of the tower is further provided with vertical track means for accommodating the shaft as it is moved vertically among different positions.